<?php

/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Service
 * @subpackage Amazon
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: ResultSet.php 16211 2009-06-21 19:23:55Z thomas $
 */


/**
 * @see Zend_Service_Amazon_Item
 */
require_once 'Zend/Service/Amazon/Item.php';


/**
 * @category   Zend
 * @package    Zend_Service
 * @subpackage Amazon
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Service_Amazon_ResultSet implements SeekableIterator
{
	/**
	 * A DOMNodeList of <Item> elements
	 *
	 * @var DOMNodeList
	 */
	protected $_results = null;

	/**
	 * Amazon Web Service Return Document
	 *
	 * @var DOMDocument
	 */
	protected $_dom;

	/**
	 * XPath Object for $this->_dom
	 *
	 * @var DOMXPath
	 */
	protected $_xpath;

	/**
	 * Current index for SeekableIterator
	 *
	 * @var int
	 */
	protected $_currentIndex = 0;

	/**
	 * Create an instance of Zend_Service_Amazon_ResultSet and create the necessary data objects
	 *
	 * @param  DOMDocument $dom
	 * @return void
	 */
	public function __construct(DOMDocument $dom)
	{
		$this->_dom = $dom;
		$this->_xpath = new DOMXPath($dom);
		$this->_xpath->registerNamespace('az', 'http://webservices.amazon.com/AWSECommerceService/2005-10-05');
		$this->_results = $this->_xpath->query('//az:Item');
	}

	/**
	 * Total Number of results returned
	 *
	 * @return int Total number of results returned
	 */
	public function totalResults()
	{
		$result = $this->_xpath->query('//az:TotalResults/text()');
		return (int) $result->item(0)->data;
	}

	/**
	 * Total Number of pages returned
	 *
	 * @return int Total number of pages returned
	 */
	public function totalPages()
	{
		$result = $this->_xpath->query('//az:TotalPages/text()');
		return (int) $result->item(0)->data;
	}

	/**
	 * Implement SeekableIterator::current()
	 *
	 * @return Zend_Service_Amazon_Item
	 */
	public function current()
	{
		return new Zend_Service_Amazon_Item($this->_results->item($this->_currentIndex));
	}

	/**
	 * Implement SeekableIterator::key()
	 *
	 * @return int
	 */
	public function key()
	{
		return $this->_currentIndex;
	}

	/**
	 * Implement SeekableIterator::next()
	 *
	 * @return void
	 */
	public function next()
	{
		$this->_currentIndex += 1;
	}

	/**
	 * Implement SeekableIterator::rewind()
	 *
	 * @return void
	 */
	public function rewind()
	{
		$this->_currentIndex = 0;
	}

	/**
	 * Implement SeekableIterator::seek()
	 *
	 * @param  int $index
	 * @throws OutOfBoundsException
	 * @return void
	 */
	public function seek($index)
	{
		$indexInt = (int) $index;
		if ($indexInt >= 0 && (null === $this->_results || $indexInt < $this->_results->length)) {
			$this->_currentIndex = $indexInt;
		} else {
			throw new OutOfBoundsException("Illegal index '$index'");
		}
	}

	/**
	 * Implement SeekableIterator::valid()
	 *
	 * @return boolean
	 */
	public function valid()
	{
		return null !== $this->_results && $this->_currentIndex < $this->_results->length;
	}
}
